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PROTECTION 



OF 



IRON and STEEL 



AGAINST 



CORROSION 



The "Standard" 
Galvanizing Process 



Copyright, 1913 



The Metal Treating and Equipment Go, 

Incorporated 

United States Rubber Go. Building 
NEW YORK 






Table of Contents 



PAGE 

1. CORROSION 3 

Protecting Agents 4 



2. GALVANIZING 7 

Hot Galvanizing 7 

Sherardizing 9 

Electro-Galvanizing 10 

3. THE "STANDARD" GALVANIZING PROCESS 14 

"Standard" Equipment 17 

4. HOW TO FIGURE GALVANIZING EQUIPMENT 1 9 

Power Economy and Equipment 19 



Send Us Your Inquiries 
We Are at Your Service 



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CLA34817C 



For Protection oj Iron and Steel Against Corrosion 



Protection of Iron and Steel 
Against Corrosion 

1. CORROSION 

The surface of articles made of iron or steel will rapidly 
oxidize and decay when exposed to the action of the ele- 
ments. Such corrosion is due generally to a chemical action 
taking place between the molecules of the metal and the 
corroding agents; for any metal, the greater the impurities 
it contains, the greater the corrosion. 

This is in reality due to an electro-chemical or galvanic 
action taking place between the metal and the impurities, 
both in presence of moisture, and since the impurities con- 
tained are usually electro-negative to the iron, the latter will 
constitute the anode in the minute cells thus formed, and 
will corrode much more rapidly than if no impurities were 
present. 



In iron and steel work, too, "an ounce of pre- 
vention is worth a pound of cure, " 



The agents of corrosion are, therefore, of two distinct 
natures, viz.: 

Chemical action. 
Electro-chemical action. 

Use the "Standard" Galvanizing Process 
3 



For Protection of Iron and Steel Against Corrosion 

In the following series every metal is electrically pos- 
itive to a metal below it, and electrically negative to a 
metal above it. 

1. Magnesium. 12. Bismuth. 

2. Aluminum. 13. Arsenic. 

3. Manganese. 14. Antimony 

4. Zinc. 15. Tin. 

5. Cadmium. 16. Copper. 

6. Thallium. 17. Mercury. 

7. Iron. 18. Silver. 

8. Cobalt. 19. Palladium. 

9. Nickel. 20. Platinum. 

10. Lead. 21. Gold. 

11. Hydrogen, 

As a general rule the farther the electro-negative metal 
in said series from the electro-positive, the more rapid and 
energetic the corrosion of the latter in the presence of 
moisture or other corroding agents. 



The selecting of a proper method for treating 
your work is more than effecting an economy and 
more than the exercising of sound judgment ; it is 
the performance of a duty; proper protection 
often means insuring the safety of other people's 
lives. 



PROTECTING AGENTS. 

From the foregoing it is apparent that in order to pre- 
vent corrosion it is necessary to protect the surface of the 
iron or steel from contact with moisture and other cor- 
roding elements. The various paints and varnishes used 
for this purpose are not satisfactory, inasmuch as they are 
subject to more or less rapid chemical changes which 

Use the "Standard" Galvanizing Process 

4 



For Protection of Iron and Steel Against Corrosion 

cause them to peel off or to become porous, and therefore 
to lose their efficiency. 

The coating of the surface with another metal less 
liable to be attacked by the usual corroding agents is the 
next most natural solution of the problem. This provides 
a coating that is less liable to wear than the usual paints, is 
not subject to rapid chemical changes, and therefore 
affords a better and more durable protection to the under- 
lying metal. 

THERE ARE A FEW IMPORTANT POINTS, 
HOWEVER, THAT MUST NOT BE FORGOTTEN: 

1. Iron and steel articles are often subjected to me- 
chanical causes of wear, like handling, shocks, etc., which 
may produce damage to the coating in certain spots, and 
actually cause the local destruction of the same, as happens 
in some machining operations, like drilling holes or punch- 
ing sheet metal after plating, In such cases, when the local 
mechanical protection is lost, galvanic action sets in, and 
if the metal coating is electro-negative to the iron, the 
corrosion of the latter is greatly hastened. 

It follows, therefore, that, aside from their excessive 
cost, and from qualities and considerations which make them 
best suited for certain uses, coatings of tin, or nickel, or 
copper, are little adapted for the protection of iron, unless 
the coating is heavy, and not liable to be destroyed in certain 
points. In tinplate, for instance, once the continuity of the 
surface is destroyed, corrosion starts immediately, and pro- 
gresses much more rapidly than if no tin were present. 

Zinc, on the other hand, is positive to iron, and there- 
fore even when the coating is partly broken away, and the 
mechanical protection thereby lost, the electro-chemical 
protection still remains, the presence of zinc continuing to 
prevent the corrosion of the iron to a remarkable extent. 

Use the "Standard" Galvanizing Process 
5 



For Protection of Iron and Steel Against Corrosion 

In addition to this, zinc offers a further advantage as 
a protective agent inasmuch as when it is exposed to 
moist air, it becomes covered with a white film of a basic 
zinc carbonate, which will effectively prevent further decay 
of the zinc itself. 

2. The production of metallic coatings (which can 
be obtained both electrolytically and by immersion in baths 
of molten metal), unfortunately, usually requires pickling 
operations in acid solutions which are liable to leave a trace 
of acidity on the surface of the articles ; this acidity may be 
partly destroyed, but in certain processes of electro-deposi- 
tion the SOLUTIONS THEMSELVES ARE ACID TO 
A CONSIDERABLE EXTENT, and are liable to start 
corrosion even before the deposition of the coating is started. 
In these cases, which are not the exception by any means, 
the enemy is right there, concealed underneath the coating ; 
and while the appearance of the work is quite satisfactory 
when the same leaves the factory, it does not take long 
before the rust shows through. Buyers and users of electro- 
plated goods are quite familiar with this serious incon- 
venience, which is more prominent in connection with elec- 
tro-galvanized goods produced by means of certain pro- 
cesses in which slow and acid solutions are employed. 

3. While from the above it follows that zinc is UN- 
QUESTIONABLY the BEST means for protecting iron 
against corrosion, since it affords both a mechanical and 
a galvanic protection, it also follows that the metallic coat- 
ing itself, in order to offer the maximum resistance to the 
action of corroding agents, must be free from acidity and 
in as chemically pure a state as possible. As above stated, 
a metal is more easily corroded when impure, and this is 
especially true in connection with zinc, where two per cent, 
impurities already cause an enormous difference in the 
behavior of the metal. This can be easily demonstrated by 
exposing impure zinc and chemically pure zinc to the action 

Use the "Standard" Galvanizing Process 
6 



For Protection oj Iron and Steel Against Corrosion 

of a weak solution of sulphuric or other acid ; the evolution 
of hydrogen will be much more energetic in connection with 
the impure than with the pure zinc, which takes far more 
time to dissolve in the same proportion. 



Do not judge galvanized work by appearance ; 
remember, the real test is durability. 



2. GALVANIZING 

The word galvanizing as applied to the coating of iron 
and steel articles with zinc, derives its meaning from the 
protection against galvanic action given by the latter to the 
former, as already described. There are three distinct 
methods for galvanizing, commercially applied : 

Hot Galvanizing, 

Sherardizing, 

Electro-galvanizing. 

HOT GALVANIZING. 

Hot galvanizing is the oldest known process for coat- 
ing iron with zinc, and consists in dipping the articles into 
a bath of molten spelter, a soldering flux being employed 
to cause the spelter to adhere to the surface of the articles. 

While this process is used to a large extent, it is pos- 
sessed of many objectionable features and disadvantages 
which may be summarized as follows: 

1. The zinc deposited is impure, and the percentage 
of the impurities contained gradually increases with use, 
since some iron from the pot as well as from the articles 
will combine with it. These impurities greatly hasten the 

Use the "Standard" Galvanizing Process 

7 



For Protection of Iron and Steel Against Corrosion 



corrosion of the zinc itself, which therefore after a certain 
time, ceases to be a protective layer for the underlying iron. 

2. Such impurities further render the zinc coating so 
brittle that a piece of sheet metal or wire thus treated can 
hardly be bent or twisted without cracking. 

3. The thick coating of zinc fills in the interstices of 
perforated metal and fills the threads of threaded articles 
like bolts and nuts ; this makes rethreading necessary. This 
operation is costly and besides that totally removes the zinc 
coating and its protective action. Expanded metal and 
other articles of irregular form with many edges can be 
galvanized only at great expense because the zinc, deposited 
in a thick layer and in lumps, renders the cost of the opera- 
tion well nigh prohibitive. 

The molten zinc volatilizes in the air, giving off poi- 
sonous fumes, injurious to workmen; furthermore, the 
amount of zinc lost in this manner and on account of the 
dross and skimmings formed is very considerable and varies 
usually between 30 and 40 per cent. 

4. The hot galvanizing process requires night and day 
work, large tanks are difficult to manage and great care is 
necessary in dipping the articles slowly and in a dry con- 
dition to prevent spattering of the metal ; this allows the 
formation of a coating of oxide underneath the zinc coating, 
which greatly impairs the adherence of the latter. 

5. When a hot galvanizing plant is not operated con- 
tinuously the spelter must be allowed to cool and harden, 
and under these conditions it is necessary to exercise great 
care to prevent the burning of the bottom of the pot; the 
renewal of the galvanizing pots is quite an item of expense 
with which the hot galvanizer has to figure, and the same 
may be said of the loss of spelter which occasionally takes 
place when a pot cracks or breaks. 

Use the "Standard" Galvanizing Process 



For Protection of Iron and Steel Against Corrosion 

6. The impure zinc coating is hard on tools and dies, 
on which it exerts a grinding action ; this will dull the edges 
of cutting tools very quickly and will necessitate therefore 
the frequent grinding of the same, which is costly; this in- 
convenience is so serious that some firms refuse to guar- 
antee and even to make blanking or cutting dies to be used 
in connection with sheet metal galvanized by the hot pro- 
cess. 



What galvanized work should show : 

Durability, 

Adherence and ductility of coating, 

Low cost, 

Good appearance. 
Your work will possess these qualities to a 
superlative degree if you use the "Standard" Solu- 
tion and Equipment. 



SHERARDIZING. 

This is a process of recent introduction and consists in 
packing the articles to be coated in zinc dust in an air-tight 
drum, which is then exposed to heat. 

This process seems to give fairly satisfactory results, 
especially in connection with small articles and small cast- 
ings, but it is apparently open to objections of a serious 
nature. 

1. The zinc iron alloy which is formed on the surface 
of the article, show widely varying amounts of iron present. 
Where the theoretical alloy corresponding to FeZn 10 con- 
taining about 9 per cent, of iron has been obtained, a coat- 
ing material resistant to corrosive action has resulted. The 
amount of iron, however, seems to depend largely upon the 
temperature used, and since it is extremely difficult to con- 

Use the "Standard" Galvanizing Process 
9 



For Protection of Iron and Steel Against Corrosion 

trol the temperature inside of a drum, zinc dust being a 
poor conductor of heat, it is consequently extremely diffi- 
cult to know whether the alloy that has been formed is 
the right one or not. 

2. The more iron contained in the coating the more 
quickly will it corrode, and with coatings containing from 
25 to 30 per cent, of iron, little protection is afforded to 
the underlying metal, since the coating pits easily. 

3. It being practically impossible to obtain an even 
temperature both at the center and at the periphery of the 
drum, the process is necessarily limited to articles of a small 
size. 

4. The appearance of the surface of the articles treated 
is not uniformly good, a considerable proportion of the same 
having a dark gray color ; this is due apparently to the vary- 
ing conditions of temperature to which the articles are 
exposed at various points in the drum. 



A comparatively light coating of pure electro- 
lytic zinc will give a better protection than a 
coating twice as heavy of zinc containing even a 
small proportion of impurities. 



ELECTRO-GALVANIZING. 

This process consists in depositing zinc on iron by 
means of electrolysis and is possessed of many important 
advantages, as follows : 

1. Only chemically pure zinc is deposited. 

2. The quantity of zinc deposited can be controlled 
at will. 

3. The plant is always ready for work. 

Use the "Standard" Galvanizing Process 

10 



For Protection of Iron and Steel Against Corrosion 

4. There is no limit to the size of the articles that 
can be treated. 

5. Netting, perforated articles, metal lath, expanded 
metal, bolts, nuts and other threaded articles can be gal- 
vanized satisfactorily at a low cost without need of re- 
threading the latter. 

6. Sheet metal and steel articles may be galvanized 
without harm to their shape or to their physical structure. 

7. The process can be carried on with the employment 
of unskilled labor. 



What must be avoided in a galvanizing solution : 

Acidity, 

Lack of conductivity (slowness of operation, 
unnecessarily large size of plants), 

Lack of permanency, (need of additions of 
chemicals), 

Formation of gases (production of a porous 
coating), 

Need of agitation and of artificial heating, 

Lack of ability to work between wide ranges 
of voltage, 

Poisonous exhalations, 

Limited thickness of deposit. 



However, electro-galvanizing processes have not 
been applied as largely as the advantages just 
mentioned would warrant, and this mainly because many 
solutions used for this purpose are open to very serious 
objections. The principal objections made to the usual 
cold or electro-galvanizing processes are, that the zinc 
coatings produced are much less durable than those ob- 

Use the "Standard" Galvanizing Process 
11 



For Protection of Iron and Steel Against Corrosion 

tained by hot galvanizing, and that the results are slow 
and rather uncertain on articles having an irregular surface. 

These objections are unfortunately justified, as regards 
the majority of solutions on the market, the unsatisfactory 
results obtained being due principally to the following 
reasons : 

1. Poor conductivity and therefore slowness in action 
of the solution: if the solution is acid as is usually the 
case, this may leave a trace of acidity underneath the zinc 
coating that will cause rust to show through after a few 
weeks or months, even if the articles are not exposed to the 
elements. 

2. Inability of the solutions to plate without the 
evolution of gases : while a very thin coating of a good struc- 
ture (usually .2 to .3 ounces per sq. ft.) can be obtained, 
after this the deposit is porous and of no protective value. 

3. Slowness in operation, due to poor conductivity of 

the solution : this necessitates the installation of very large 
plants for a given output. 

4. The lack of permanency in the solutions: these 
lose their strength very soon and need to be kept up 
by the additions of chemicals. The zinc being mainly taken 
from these chemicals, it is obvious that its cost is consider- 
ably higher than that of commercial metallic zinc. From 
a technical standpoint however, this inconvenience is much 
more serious since it is a well known fact that electro-plat- 
ing solutions work at their best only when they are well 
ionized (or electrolysed). It usually takes two or three 
days of work to bring a galvanizing solution to this condi- 
tion, and the trouble with non-permanent solutions is that 
when they begin to give fairly good results, they also begin 
to be impoverished and will therefore require the addition of 
chemicals after a short time ; this addition renders the solu- 

Use the "Standard" Galvanizing Process 
12 



For Protection of Iron and Steel Against Corrosion 

tion again practically new and therefore needing regener- 
ation and hardly fit for good work. 

5. The poor conductivity of the solution is also re- 
sponsible for the difficulties in coating articles having an 
irregular surface, and makes it also impossible to satisfac- 
torily galvanize inside corners of boxes and recesses; this 
is obviously due to the limited intensities of current ob- 
tainable. 

6. Necessity of agitating and regenerating the solu- 
tions and in some cases also of heating the same, the results 
not being satisfactory at usual room temperatures. 

7. Extreme care required in pickling operations. 

8. Inability to produce deposits that will stand the 
usual tests required by the government, by telephone and 
telegraph companies, railroads, architects, etc. 



Zinc coating that makes for good galvanized 
work will show : 

Freedom from acidity, 
Freedom from porosity, 
Chemical purity, 
Sufficient thickness, 
Continuity of surface. 

These qualities will always be found in zinc 
coatings obtained by means of the "Standard" 
Solution and Equipment, 



These serious inconveniences have naturally hampered 
the development of electro-galvanizing; while labor saving 
appliances have been devised to reduce the cost of handling 
materials, yet also in this field there is vast room for im- 
provements ; altogether, as an engineering proposition elec- 

Use the "Standard " Galvanizing Process 

13 



For Protection of Iron and Steel Against Corrosion 

tro-galvanizing has so far been unduly neglected; this of 
course being in its turn largely due to the lack of a 
satisfactorily working solution. 



Zinc is the best friend of iron ; acidity is the 
worst enemy of zinc coatings, and hydrogen gas 
is next. 



3. THE "STANDARD" GALVANIZ- 
ING PROCESS. 

This comprises the "Standard" Solution and the 
"Standard" Equipment, the advantages of which we will 
now point out in brief form : 

The Standard Process is a cold or-electro-galvanizing 
process, possessed of all the advantages of electro-galvaniz- 
ing already mentioned, without any of the objectionable 
features ; we can say therefore without hesitation that it is 
by far the best process in existence. 

The Standard Solution has a very high conductivity, 
containing a high percentage of metallic zinc ; and at parity 
of conditions of temperature and voltage will conduct 
about twice as much current as the average solutions, or in 
other words, will give the same deposit in half the time. 
It is however possible with this solution to work with higher 
voltages than with the usual solutions, and reduce the time 
of operation by 75 per cent, if necessary. This means that it 
is possible to obtain densities of current which cannot be 
obtained by other solutions, and it is therefore possible to 
galvanize certain articles having an irregular shape that 
could not be satisfactorily treated by means of other 
solutions. 

Use the " Standard" Galvanizing Process 

14 



For Protection of Iron and Steel Against Corrosion 

There is no liberation of gases either at the anode or 
at the cathode, and this causes the coating to be extremely 
adhesive, dense, ductile, and in fact both in quality and in 
appearance such as no average solution could heretofore 
produce. Sheet metal or wire galvanized with this solution 
can be bent, twisted, hammered flat, formed in dies, etc. 
without a sign of cracking or peeling of the coating 

Nothing but pure metallic zinc is deposited, and the 
same can be deposited in any quantity, and always of a 
tough and metallic structure; the deposit is never porous 
and work can be produced to stand the severest tests, the 
usual copper sulphate test and the durability test included. 

The solution is practically neutral or very slightly acid ; 
this renders impossible the corrosion of articles previous 
to plating, and moreover this is further prevented by the 
fact that the action of the solution is so immediate that the 
deposit of zinc is started practically at the same moment 
that the article is attached to the cathode bar. 

The solution is permanent and therefore always in the 
best condition for work, and can be worked for 24 hours 
per day, day in and day out. 

No addition of chemicals being required and the zinc 
taken from the solution being replaced entirely from the 
anodes, a considerable economy is effected in comparison 
with solutions taking the zinc from zinc salts added to the 
solution; the anodes used in connection with the Standard 
Solution are of commercial zinc and the impurities that 
they may contain are not deposited on the work, but will 
collect on the bottom of the tank. It is not necessary to 
agitate or to heat the solution, which works well at usual 
room temperature ; the solution does not give off poisonous 
or dangerous fumes. 

Use the "Standard" Galvanizing Process 

15 



For Protection of Iron and Steel Against Corrosion 

A tank of a given size has an output about double the 
one obtainable with the use of other solutions, and therefore 
for a given output a considerable economy in space and first 
cost of installation may be effected. There is no limit to the 
size of articles which can be galvanized. 

While the articles to be galvanized have to be carefully 
cleaned, this operation does not require the extreme care 
which is required by other solutions, nor as strong acid 
pickling solutions. There is no trace of acidity left on the 
surface of the work, previous to or during the plating 
operation. 

Zinc coatings produced by the Standard Solution have 
a beautiful appearance, being glossy white and bright, and 
retain the same longer than any other zinc coating. The 
Standard Galvanizing Solution improves with use. 



A solution that makes for economy and quality in 
electro- galvanized work will show : 

Freedom from acidity, 

Freedom from generation of gases, 

Permanency, (ability to regenerate itself from 
the anodes), 

High conductivity, 

Ability to work well without agitation and 
without necessity of heating. 

Ability to work well between wide limits of 
voltage, 

Freedom from poisonous exhalations, 

Ease of upkeep and freedom from necessity of 
regenerating or doctoring. 

All these qualities meet together in the "Stan- 
dard" Electro-Galvanizing Solution. 



Use the "Standard" Galvanizing Process 
16 



For Protection of Iron and Steel Against Corrosion 

"STANDARD" EQUIPMENT 

The Standard Electro-Galvanizing Equipment is com- 
posed of a number of machines and apparatuses which we 
are continuously developing for the handling of different 
materials both for pickling and for galvanizing, so as to re- 
duce to a minimum the expense for labor entailed by gal- 
vanizing operations. 

We realize, however, that it is almost impossible to 
develop a complete line of appliances to take care of all and 
every need of the manufacturers ; therefore, our engineering 
department makes a specialty of devising, designing and 
installing special plants and apparatuses, according to the 
special work of any individual manufacturer. 



The man who tries to make the cheap equip' 
ment do the work of the best is wasting more 
money than the best would cost. 



In this direction we take the greatest pains to reach 
perfection as far as possible, since we realize that once we 
have the tool, that is our Standard Solution, the real prob- 
lem lies in the correct design and installation of plants. We 
emphasize this point, that we want to co-operate with our 
customers in every possible way, and all we require is that 
complete data, and possibly blue prints and samples, be sent 
to us showing the different articles to be galvanized, the 
total output, the thickness of zinc desired, the tests which 
the articles have to withstand, and all possible data relating 
to the floor space and to the facilities which are at the dis- 
posal of the manufacturer, which may enable us to intelli- 
gently submit our plans. 

We can in this way absolutely guarantee the highest, 
most economical and very best results which can be ob- 
tained by electro-galvanizing. 

Use the "Standard " Galvanizing Process 

17 



For Protection of Iron and Steel Against Corrosion 



The labor-saving device that will save the most 
is certainly the one which is cheapest to buy. 



We will gladly give any information desired relating 
to electro-galvanizing plants of any character and size, and 
will be pleased to galvanize your own samples and then 
install plants guaranteeing duplication of results. We will 
also furnish estimate of cost of installation of plants and 
also cost of production for a given output and thickness of 
coating, and are always ready in all instances to guarantee 
our figures. 

We are also prepared to fit your own plant with our 
"Standard" Solution, guaranteeing a considerable improve- 
ment on the present results, and will also be glad to assist 
our customers in improving the design of their plants from 
an engineering standpoint. 



An electro- galvanizing apparatus which can 
be used for all kinds of articles is usually not 
much good for any of them. 



Our process has been reported on most favorably by 
the Government, by Telegraph and Telephone Companies, 
and by many leading concerns; if you want to know what 
users think of it, we will refer you to any of our customers. 



The zinc deposited from the chemicals added 
to the usual salt solutions costs you 45 cents a 
pound, since it takes four and a half pounds of 
zinc salts to furnish one pound of zinc ; commer- 
cial zinc costs six cents a pound. Which are you 
going to use ? 



Use the "Standard" Galvanizing Process 
18 



For Protection of Iron and Steel Against Corrosion 

4. HOW TO FIGURE GALVANIZING 
EQUIPMENT 

1. Figure the amount of surface in square feet to be 
coated per hour. 

2. Multiply this amount by the quantity of zinc per 
square foot you want to deposit, in ounces (for a good com- 
mercial coating usually 0.4 ounces per sq. ft. ; for a medium 
heavy coating 0.5 ounces per sq. ft.; and for a heavy coat- 
ing from 0.6 to 1 ounce per sq. ft.). 

3. Multiply the number of ounces of zinc to be de- 
posited by 25 ; this will give the number of amperes that 
must be continuously provided by the dynamo; 1,000 am- 
pere-hours will deposit theoretically 42.8 ounces of zinc, 
but in practice, owing to the percentage of impurities 
present in the zinc anodes, 1,000 ampere-hours will deposit 
40 ounces, or 2J^ pounds of zinc. 



If you can do the work of a 2, 000 gallon tank 
in a 1,000 one, you save half the space, with the 
saving of equipping one additional tank with 
connections, solutions and anodes thrown in. 



POWER ECONOMY AND EQUIPMENT. 

The quantity of zinc deposited on the surface exposed 
is not proportional to the amount of power spent, but is in 
proportion only to the intensity of the current, or to the 
number of amperes delivered by the dynamo. One ampere 
flowing for one hour will deposit .00033696 grams of zinc, 
this being the electro-chemical equivalent of zinc. If ten 
amperes are flowing for one hour at 3 volts, the power spent 
will be 10 X 3 = 30 watt-hours, while the deposit of zinc 
obtained will be .00033696 X 10 grams. 

Use the "Standard" Galvanizing Process 
19 



For Protection of Iron and Steel Against Corrosion 

If 10 amperes are flowing for one hour at 6 volts, the 
power spent will be 10 X 6 = 60 watt-hours, or double the 
amount of power spent in the preceding case, the deposit 
obtained remaining the same. 

To give an example which is more consistent with 
actual practice, and remembering that in electricity volt- 
age = resistance X intensity, let us suppose we have a 
surface of one square foot exposed in the tank that under 
given conditions of resistance shows 20 amperes at the am- 
meter with 3 volts at the poles; if we leave the conditions 
of resistance unaltered and we double the voltage, the in- 
tensity of current will also be doubled, and 40 amperes will 
show at the ammeter. 

The same amount of zinc deposited by 20 amperes for 
one hour will be deposited by 40 amperes in one-half hour ; 
but in the first instance the power spent will be 20 X 3 = 
60 watt-hours, while in the second instance the power will 

40 X 6 

be = 120 watt-hours. It is thus seen that the 

2 
power spent is proportional to the amount of zinc deposited, 
and to the voltage at which said deposition takes place. 

It is therefore apparent that from the standpoint of ex- 
penditure of power, it is preferable to use as low a voltage 
as consistent with the number of amperes to be provided 
per square foot of surface exposed. 



To obtain the weight of zinc deposited by a 
given current in a given time : multiply the num- 
ber of amperes by the number of hours, and divide 
by 400 ; the result will be the weight of zinc 
in pounds, or divide by 25, the result will be the 
weight of zinc in ounces. 



Use the "Standard" Galvanizing Process 
20 



For Protection of Iron and Steel Against Corrosion 

There are two distinct points to be considered in an 
electro-galvanizing solution : 

1. Capacity of working satisfactorily at voltages 
higher than those used by another solution. 

This is not in reality for the solution considered, to 
possess a higher conductivity, while at the same time the 
solution may of course do the work in half the time, for the 
reasons explained. The majority of solutions only work 
well at low voltages, usually 3 volts ; higher voltages cause 
the evolution of too much hydrogen, and therefore spongy 
deposits. 

Other and better solutions are capable of working also 
at higher voltages, with proportionally increased speed, but 
also with a proportional increase in expense for power. The 
increased power spent will go to heat the solution, with 
the result that when the same becomes too hot the voltage 
has to be lowered. This capacity to develop higher inten- 
sities of current, however, constitutes a decided advantage, 
in some cases even at an increased expense for power. 

2. Capacity of conducting more current than another 
solution under the same conditions of voltage and of circuit 
resistance; this is really for a solution to possess a higher 
conductivity than another. 

THE STANDARD GALVANIZING SOLUTION 
POSSESSES BOTH HIGH CONDUCTIVITY AND 
CAPACITY OF WORKING AT HIGH VOLTAGES, 
WITH THE RESULT THAT: 

Voltages being equal, the solution will conduct more 
current than any other solution on the market, and about 
twice as much as the usual solutions will; this makes for 
speed in results, without increased expense for power, and 
also makes for more uniform coatings on irregular surfaces. 

Use the "Standard" Galvanizing Process 

21 



For Protection of Iron and Steel Against Corrosion 

Voltage being higher, the capacity to conduct current 
will still be increased in proportion, and therefore the high 
intensities obtainable give the possibility of galvanizing 
articles having very irregular surfaces with points and re- 
cesses difficult to reach, that it would otherwise not be pos- 
sible to treat by means of other solutions. 

When you consider a solution for your electro-galvan- 
izing plant, see that same be able to show more amperes 
than another with conditions of voltage and circuit resist- 
ance being equal ; this is to possess higher conductivity. 

In a solution always see that same be able to work at 
a higher voltage than another; this makes for increased 

speed, altho', it is true, with increased expense for power. 

The best solution is the one which will show more 
amperes at the same voltage and same conditions of circuit 
resistance, and which will also be capable of working satis- 
factorily at the higher voltages. 

HERE IS A PARTIAL LIST OF ARTICLES FOR 
WHICH OUR GALVANIZING PROCESS IS WELL 
SUITED : 

Sheet Metal, Bolts, nuts, washers, lag 

Expanded Metal, screws, 

Pipes, Marine hardware, 

Chains, Plumbers hardware, 

Electrical Conduit, Wire goods, 

Bar iron, Clamps, 

Structural Steel of all descrip-Hinges, 

tion, Nails, 

Hoops and bands, Sheet metal wheels, 

Wire, barb wire, Pulleys, 

Perforated metal, Pipe fittings, 

Use the "Standard" Galvanizing Process 
22 



For Protection of Iron and Steel Against Corrosion 

Automobile bodies, BoilerTubes, 

Conduit boxes, Spiral Pipe, 

Telephone and telegraph Railway supplies, 

pole fittings, Braces, 

Rail joints, Lock Washers. 
Culverts, 

and in general all articles made of iron and steel which are 
to be exposed to the action of the elements. 



SEND US YOUR INQUIRIES 
WE ARE AT YOUR SERVICE 



The Metal Treating and Equipment Go, 

Incorporated 

U. S. Rubber Co. Building 
New York 



Use the "Standard" Galvanizing Process 

23 



MAY 12 1913 



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